Visual display devices are well known and include cinematic film projectors, television sets, monitors, plasma displays, liquid crystal display LCD televisions, monitors, and projectors etc. Such devices are often employed to present images or image sequences to viewer.
The field of backlighting began in the 1960s due to the fact that televisions require a “darker” room for optimal viewing. Backlighting is in its simplest form white light, emitted from e.g. a light bulb, projected on a surface behind the visual display device. Backlighting has been suggested to be used to relax the iris and reduce eye strain.
During recent years the backlighting technology has become more sophisticated and there are several display devices on the market with integrated backlighting features that enables emitting colors with different brightness depending on the visual information presented on the display device.
The benefits of backlighting in general include: a deeper and more immersive viewing experience, improved color, contrast and detail for best picture quality, and reduced eye strain for more relaxed viewing. Different advantages of backlighting require different settings of the backlighting system. Reduced eye strain may require slow changing colors and a more or less fixed brightness while more immersive viewing experience may require an extension of the screen content i.e. the same brightness changes with the same speed as the screen content.
However, current backlighting systems are quite expensive and therefore there is a need of providing backlighting systems with reduced costs. Moreover, it would also be advantageous to reduce the depth size or thickness of current backlighting systems.